Welcome to this forum!
To keep a veiled chameleon healthy in captivity its necessary to provide the proper husbandry and nutrition. If you don't there will be health issues.
She needs a full spectrum light that includes UVB. The UVB allows her to produce vitamin D3 which enables her to use the calcium she is provided with. The light must not pass through glass or plastic.
Insects should be gutloaded (fed a nutritious diet to ensure that they are healthy) before being given to the chameleon. They need to be dusted with a calcium powder (that has no phosphorous in it) because insects generally have a poor calcium to phosphorous ratio.
If she is only kept indoors and gets no sunlight (that doesn't pass through glass or plastic), then I recommend dusting the insects lightly with a calcium/D3 powder twice a month before feeding them to her.
I also recommend a vitamin/mineral powder be dusted lightly on the insects before you feed them to her twice a month. If the vitamin A in the powder does not come from a beta carotene source it can be overdosed. Vitamin D from supplementation can also be overdosed. Vitamin A and vitaminD3 and calcium and phosphorous are the main players in bone health and need to be balanced.
Veileds are omnivores once they are about 6 months of age, so any plants that you use in her cage should be non-toxic and well washed (both sides of the leaves). They can/will eat the leaves of the plants and greens (dandelion greens, kale, collards, endive, ROMAINE lettuce, mustard greens, etc.), veggies (sweet red pepper, squash, sweet potato, zucchini, carrot, etc.) and fruit (apple, pear, melon, berries, etc.) if you offer it to them. If they don't eat it then chances are that the insects will...so she will still end up with that nutrition.
I do not recommend the use of substrates with veileds...too many of them can cause impaction.
Temperature plays a part in digestion and absorption of nutrients.
Hydration is important for renal function, etc., so keep her well hydrated.
Female veileds can lay eggs even when they haven't been mated, so when she reaches the age of about 6 months its important to have a suitable place for her to dig to lay the eggs. If you don't provide this, she could become eggbound and die. Also, females can lay huge clutches. If she is not overfed the clutches will be smaller.
Here are some sites that contain good information that you might like to read....
http://adcham.com/
http://www.chameleonnews.com/
http://www.chameleonjournals.com/vet/
Hope I haven't overwhelmed you and that I have covered enough that your chameleon will do well for you! Although they are not the easiest lizard to keep in captivity, they are one of the mose interesting.